Inhibition of PTTG1 expression by microRNA suppresses proliferation and induces apoptosis of malignant glioma cells

PTTG1 alleviates acute alcoholic liver injury by inhibiting endoplasmic reticulum stress-induced hepatocyte pyroptosis

BACKGROUND & AIMS

Heavy drinking is a primary cause of alcoholic liver injury (ALI). Pituitary tumour transforming gene 1 (PTTG1) is involved in the occurrence and development of hepatocellular carcinoma (HCC), which is a well-known inflammation-related cancer with various aetiologies, including alcohol consumption. However, the role of PTTG1 in alcohol-induced liver injury and inflammation is not clear.

METHODS

Blood samples were collected from patients with acute alcohol intoxication (n = 20) and healthy controls (n = 20). PTTG1 knockout (KO) mice and PTTG1 transgenic (TG) mice were given a single gavage of alcohol (5 g/kg, 50%) to construct the alcohol-induced liver injury.

RESULTS

We found that serum PTTG1 levels were downregulated in acute ALI patients. In addition, acute alcohol administration significantly reduced PTTG1 levels in the serum and liver of mice. Compared to wild-type mice, PTTG1 KO mice had more serious liver injury, which was accompanied by worsened hepatic endoplasmic reticulum (ER) stress and hepatocyte pyroptosis induced by alcohol. Similarly, PTTG1 deficiency exacerbated alcohol-induced cell death in primary mouse hepatocytes and LO2 cells, by increasing hepatic ER stress and pyroptosis. Importantly, TUDCA, an ER stress inhibitor, could blocked alcohol-induced hepatic pyroptosis in PTTG1 knockdown LO2 cells. Finally, overexpression of PTTG1 substantially attenuated alcohol-induced liver injury by reducing ER stress and hepatic pyroptosis in mice.

CONCLUSIONS

We demonstrated that PTTG1 participates in ALI and has a protective effect against alcohol-induced hepatic ER stress and pyroptosis.

Bioinformatic Analysis of PTTG Family and Prognosis and Immune Cell Infiltration in Gastric Cancer

Gastric cancer is the sixth highest incidence rate in the world. Although treatment has made progress, the prospect of gastric cancer patients is bleak. Difficulties and future prospects of immunotherapy in cancer treatment. Adaptive cell therapy, cancer vaccines, gene therapy, and monoclonal antibody therapy have all been used in gastric cancer with some initial success. PTTGs (pituitary tumor-transforming genes) have been proven to be closely related to the prognosis of many malignant tumors. However, the prognosis and immune cell infiltration of gastric adenocarcinoma (STAD) remain unclear. We retrieved multiple databases to understand the possible activity of PTTGs and their expression in gastric cancer, as well as their relationship with clinical data, overall survival rate, first progression, and survival rate after progression. PTTGs are overexpressed in STAD tumor tissues. Many clinical variables are closely related to PTTGs. In addition, PTTG was associated with overall survival independent of disease. In addition, the expression of PTTG1/2 was positively correlated with the molecular status of the immune checkpoint and negatively correlated with the infiltration of various immune cells. Data research shows that PTTG and STAD are closely related. This paved the way for future research, revealed the complex pathophysiology of gastric cancer, and introduced an effective new treatment.

Clinical significance of securin expression in solid cancers: A PRISMA-compliant meta-analysis of published studies and bioinformatics analysis based on TCGA dataset

BACKGROUND

Numerous studies have investigated the clinical significance of securin expression in solid cancers; however, the results have been inconsistent. Hence, we performed a meta-analysis of published studies to assess the clinical value of securin expression in patients with solid cancers.

METHODS

The Chinese National Knowledge Infrastructure, Web of Science, PubMed, and EMDASE databases were searched for eligible studies (from inception up to April 2021). Bioinformatics analysis based on The Cancer Genome Atlas dataset was also performed to evaluate the prognostic value of securin expression.

RESULTS

A total of 25 articles with 26 studies were included in the meta-analysis. The results of the meta-analysis implied that high securin expression was positively correlated with unfavorable overall survival (OS) (hazard ratio = 1.52, 95% CI, 1.33-1.73; P < .001) and lymph node metastasis (odd ratio = 2.96, 95% CI, 2.26-3.86; P < .001). Consistently, our bioinformatics analysis showed that increased securin expression was associated with worse OS and shorter disease-free survival in cancer patients.

CONCLUSION

Our study indicated that securin overexpression was positively associated with metastasis and inversely related to the prognosis of patients with solid cancers. However, additional high-quality studies should be conducted to validate these findings.

Decoding the temporal and regional specification of microglia in the developing human brain

Region-related heterogeneity and state transitions of microglia are important for brain development and neurological pathogenesis. However, regional specialization and state transition in microglia during early human CNS development remain unclear. Here, we profile single-cell transcriptomes of microglia from distinct regions of the developing human brain, and combined with experimental verification, we define and characterize early microglial fate determinations related to regional specification and state transition. We identified several subclasses of neuronal gene-enriched microglia with regional specification that dynamically and transiently appeared as early brain regions formed. In contrast, immune-related microglia were regionally specialized at later stages of CNS development. Surprisingly, we discovered that region-specialized immune-related microglia exit from a relative resting state and transition into distinct active states. In addition, we experimentally verified the microglial state transition. Finally, we showed that the state transition is conserved but that there are molecular differences in developing microglia in humans and mice.

A flexible microfluidic system for single-cell transcriptome profiling elucidates phased transcriptional regulators of cell cycle

Single cell transcriptome profiling has emerged as a breakthrough technology for the high-resolution understanding of complex cellular systems. Here we report a flexible, cost-effective and user-friendly droplet-based microfluidics system, called the Nadia Instrument, that can allow 3' mRNA capture of ~ 50,000 single cells or individual nuclei in a single run. The precise pressure-based system demonstrates highly reproducible droplet size, low doublet rates and high mRNA capture efficiencies that compare favorably in the field. Moreover, when combined with the Nadia Innovate, the system can be transformed into an adaptable setup that enables use of different buffers and barcoded bead configurations to facilitate diverse applications. Finally, by 3' mRNA profiling asynchronous human and mouse cells at different phases of the cell cycle, we demonstrate the system's ability to readily distinguish distinct cell populations and infer underlying transcriptional regulatory networks. Notably this provided supportive evidence for multiple transcription factors that had little or no known link to the cell cycle (e.g. DRAP1, ZKSCAN1 and CEBPZ). In summary, the Nadia platform represents a promising and flexible technology for future transcriptomic studies, and other related applications, at cell resolution.

Glutaminase isoforms expression switches microRNA levels and oxidative status in glioblastoma cells

Background

Glutaminase isoenzymes GLS and GLS2 play apparently opposing roles in cancer: GLS acts as an oncoprotein, while GLS2 (GAB isoform) has context specific tumour suppressive activity. Some microRNAs (miRNAs) have been implicated in progression of tumours, including gliomas. The aim was to investigate the effect of GLS and GAB expression on both miRNAs and oxidative status in glioblastoma cells.

Methods

Microarray profiling of miRNA was performed in GLS-silenced LN229 and GAB-transfected T98G human glioblastoma cells and their wild-type counterparts. Results were validated by real-time quantitative RT-PCR. Oxidative status and antioxidant enzymes were determined by spectrophotometric or fluorescence assays in GLS-silenced LN229 and T98G, and GAB-transfected LN229 and T98G.

Results

MiRNA-146a-5p, miRNA-140-3p, miRNA-21-5p, miRNA-1260a, and miRNA-92a-3p were downregulated, and miRNA-1246 was upregulated when GLS was knocked down. MiRNA-140-3p, miRNA-1246, miRNA-1260a, miRNA-21-5p, and miRNA-146a-5p were upregulated when GAB was overexpressed. Oxidative status (lipid peroxidation, protein carbonylation, total antioxidant capacity, and glutathione levels), as well as antioxidant enzymes (catalase, superoxide dismutase, and glutathione reductase) of silenced GLS glioblastoma cells and overexpressed GAB glioblastoma cells significantly changed versus their respective control glioblastoma cells. MiRNA-1246, miRNA-1260a, miRNA-146a-5p, and miRNA-21-5p have been characterized as strong biomarkers of glioblastoma proliferation linked to both GLS silencing and GAB overexpression. Total glutathione is a reliable biomarker of glioblastoma oxidative status steadily associated to both GLS silencing and GAB overexpression.

Conclusions

Glutaminase isoenzymes are related to the expression of some miRNAs and may contribute to either tumour progression or suppression through certain miRNA-mediated pathways, proving to be a key tool to switch cancer proliferation and redox status leading to a less malignant phenotype. Accordingly, GLS and GAB expression are especially involved in glutathione-dependent antioxidant defence.

Suppression of PTTG1 inhibits cell angiogenesis, migration and invasion in glioma cells

Pituitary tumor-transforming gene 1 (PTTG1) has been identified as an oncogene and is overexpressed in many tumor types. However, the role of PTTG1 in glioblastoma (GBM) has not been well characterized, especially in relation to angiogenesis, migration, and invasion. In the present study, our results showed that the expression of PTTG1 was significantly higher in patients with GBM. Bioinformatic analysis showed that angiogenesis and the cell migration-related process were increased in patients with high PTTG1 expression levels; meanwhile, PTTG1 was positively correlated with marker genes of angiogenesis, migration and the evasion of apoptosis. In vitro assays showed that PTTG1 knockdown dramatically suppressed angiogenesis, migration and invasion, and increased the apoptosis of GBM cells. Moreover, our results also showed that silencing PTTG1 suppressed the activity of the TGF-β/PI3K-AKT-mTOR pathway, which induced tumor deterioration in multiple organs. Overall, our findings indicate that PTTG1 is a glioma malignant factor that promotes angiogenesis, migration, invasion, and the evasion of apoptosis, and these roles may be related to the TGF-β/PI3K-AKT-mTOR pathway. Thus, the targeted inhibition of PTTG1 might be a novel therapeutic strategy and a potential diagnostic biomarker for GBM-targeted therapies.

The long non-coding RNA PTTG3P promotes growth and metastasis of cervical cancer through PTTG1

The outgrowth and metastasis of cervical cancer (CC) contribute to its malignancy. Pituitary Tumor Transforming Gene 1 (PTTG1) is upregulated in many types of cancer, and enhances tumor cell growth and metastasis. However, the activation and regulation of PTTG1 in CC, especially by its pseudogene PTTG3P, have not been shown. Here, we detected significantly higher levels of PTTG1 and PTTG3P in the resected CC tissue, compared to the paired adjacent normal cervical tissue. Interestingly, the PTTG3P levels positively correlated with the PTTG1 levels. High PTTG3P levels were associated with poor patients’ survival. In vitro, PTTG1 were increased by PTTG3P overexpression, but was inhibited by PTTG3P depletion in CC cells. However, PTTG3P levels were not altered by modulation of PTTG1 in CC cells, suggesting that PTTG3P is upstream of PTTG1. Moreover, PTTG3P increased CC cell growth, likely through CCNB1-mediated increase in cell proliferation, rather than through decrease in cell apoptosis. Furthermore, PTTG3P increased CC cell invasiveness, likely through upregulation of SNAIL and downregulation of E-cadherin. Our work thus suggests that PTTG3P may promote growth and metastasis of CC through PTTG1.

Upregulation of PTTG1 is associated with poor prognosis in prostate cancer

Pituitary tumor-transforming gene 1 (PTTG1) is a regulator of chromosome stability. PTTG1 overexpression had been associated with tumor aggressiveness in several cancer types. To examine its prognostic utility in prostate cancer, a tissue microarray including 12 427 tumors with clinical and molecular data was analyzed by immunohistochemistry. PTTG1 immunostaining was largely absent in normal prostate epithelial cells. In cancers, staining was considered weak in 5.4%, moderate in 5.6% and strong in 0.8%. Strong staining was linked to advanced pT stage, high classical and quantitative Gleason grade, high Ki67-labeling index (all P < 0.0001) and lymph node metastasis (P = 0.0083). The prognostic impact of PTTG1 expression was independent of established preoperative and postoperative prognostic features. Comparison with molecular features revealed that PTTG1 upregulation was associated with nine of 12 common genomic deletions (P < 0.05), p53 alterations and high androgen receptor levels (P < 0.001 each), but was unrelated to the TMPRSS2:ERG fusion status. In conclusion, these data identify PTTG1 as a strong and independent prognostic feature in prostate cancer. PTTG1 measurement, either alone or in combination with other biomarkers might be instrumental for determining prostate cancer aggressiveness.

Distinct expression pattern and prognostic values of pituitary tumor transforming gene family genes in non-small cell lung cancer

Members of the pituitary tumor transforming gene (PTTG) family, including PTTG1, PTTG2 and PTTG3P, exhibit pivotal roles in the onset and progression of certain types of human cancer. However, to the best of our knowledge, a systematic study regarding the expression pattern and the prognostic values of PTTG family genes in non-small cell lung cancer (NSCLC) remains to be performed. The expression levels of PTTG family genes in NSCLC were successively determined using the Gene Expression Profiling Interactive Analysis, UALCAN and Oncomine databases. Subsequently, the Kaplan-Meier plotter database was used to assess the prognostic value of the PTTG family genes in patients with NSCLC, and to determine the associations between PTTG expression levels and the prognosis of patients based on different clinicopathological features, including cancer stage, grade, chemotherapy, radiotherapy, lymph node status, smoking history, and sex. PTTG1 was identified to be significantly upregulated in NSCLC in all three databases, whereas PTTG2 and PTTG3P were significantly upregulated in NSCLC in only the UALCAN database. Patients with NSCLC with higher expression levels of the three PTTG genes demonstrated shorter overall survival times. In summary, the results of the present study suggested that increased expression of PTTG family genes may serve as promising prognostic biomarkers for patients with NSCLC.

MicroRNA-520d-5p inhibits human glioma cell proliferation and induces cell cycle arrest by directly targeting PTTG1

Glioma accounts for the majority of primary malignant brain tumors in adults and is highly aggressive. Although various therapeutic approaches have been applied, outcomes of glioma treatment remain poor. Acquiring a better understanding of the pathogenic mechanisms is essential to the design of effective therapeutic strategies. Previous studies have found that miR-520d-5p was negatively correlated with glioma grade, but its role and mechanism in glioma progression remain largely unknown. In the present study, we reported that miR-520d-5p directly targeted the Pituitary Tumor Transforming Gene 1 (PTTG1) and functioned as a tumor-suppressor in glioma. The expression of miR-520d-5p in glioma cells and specimens were detected by Quantitative reverse transcription-PCR and Fluorescence in situ hybridization (FISH). The effects of miR-520d-5p on glioma progression was examined by cell-counting kit 8, colony formation, 5-ethynyl-2-deoxyuridine (EDU) and flow cytometry assays. Using bioinformatics and luciferase reporter assays, we identified PTTG1 as a novel and direct target of miR-520d-3p. A xenograft model was used to study the effect of miR-520d-5p on tumor growth and angiogenesis. We found that miR-520d-5p expression was significantly decreased in glioma cell lines and tissues. Overexpression of miR-520d-5p showed a significant inhibitory effect on cell proliferation and accompanied cell cycle G0/G1 arrest in U87-MG and LN229 glioma cells. PTTG1 was a novel and direct target of miR-520d-5p, and the protein expression of PTTG1 was markedly reduced after overexpression of miR-520d-5p in U87-MG and LN229 cells. Overexpression of PTTG1 reversed the inhibitory effect of miR-520d-5p on glioma cell proliferation. In vivo studies confirmed that miR-520d-5p overexpression retarded the growth of U87 xenograft tumors, which was accompanied by reduced expression of PTTG1. In conclusion, these results provide compelling evidence that miR-520d-5p functions as an anti-onco-miRNA, which is important in inhibiting cell proliferation in GBM, and its anti-oncogenic effects are mediated chiefly through direct suppression of PTTG1 expression. Therefore, we suggest that miR-520d-5p is a potential candidate for the prevention of glioblastoma.

MicroRNA-128 promotes apoptosis in lung cancer by directly targeting NIMA-related kinase 2

Background

MicroRNA‐128 (miR‐128) serves as a regulator by inducing cancer cell apoptosis, differentiation, the epithelial‐to‐mesenchymal transition process, and tumor growth by mediating different targets. NIMA‐related kinase 2 (NEK2) is aberrantly expressed in lung cancer. The miR‐128/NEK2 pathway has been reported to predict prognosis in colorectal cancer; however, the determination of a relationship between miR‐128 and NEK2 in lung cancer has remained elusive. We explored the association between miR‐128 and NEK2 in lung cancer.

Methods

MiR‐128 and NEK2 expression were examined in 15 lung cancer tissues by real time‐PCR. Lung cancer SK‐MES‐1 cells were transfected with miR‐128 mimic, an inhibitor or a negative control. MiR‐128 and NEK2 expression levels were detected using quantitative real time‐PCR and Western blot. SK‐MES‐1 cell apoptosis was performed by flow cytometry.

Results

Compared to adjacent non‐tumor tissues, miR‐128 was downregulated and NEK2 was upregulated in 15 lung cancer tissues. Lung cancer SK‐MES‐1 cells transfected with miR‐128 mimic induced a higher apoptotic rate than those transfected with the negative control. Dual luciferase assay further confirmed that NEK2 was a direct target of miR‐128 in lung cancer, and transfection with miR‐128 mimic could decrease the NEK2 protein level while the miR‐128 inhibitor increased NEK2 expression. Finally, the apoptotic effect of lung cancer cells induced by miR‐128 mimic could be reversed by NEK2 overexpression.

Conclusions

NEK2 was regulated by miR‐128 in lung cancer and miR‐128 induced lung cancer cell apoptosis by mediating NEK2 expression.

The clinical value and biological function of PTTG1 in colorectal cancer

Pituitary tumor transforming gene-1 (PTTG1) has been suggested to serve as an oncogene in several types of human tumors, but little is known about the biological function of PTTG1 in colorectal cancer. PTTG1 mRNA and protein expressions in colorectal cancer tissues and cell lines were measured by qRT-PCR, western blot or immunohistochemistry. The association between PTTG1 protein expression and clinicopathological features was analyzed. The function of PTTG1 on colorectal cancer cell proliferation and metastasis were explored through MTT, colony formation, migration and invasion assays. In our results, PTTG1 mRNA and protein expressions were increased in colorectal cancer tissues and cell lines compared with normal colonic tissues and colon epithelial cell line. PTTG1 overexpression positively associated with clinical stage, T classification, N classification, M classification and differentiation. The univariate and multivariate analyses suggested PTTG1 overexpression was an independent poor prognostic factor for colorectal cancer patients. The in vitro experiments showed knocking down PTTG1 inhibited colorectal cancer growth and metastasis. In conclusion, PTTG1 is an independent prognostic factor and acts as an oncogene in colorectal cancer.